This invention relates generally to vehicle convertible tops and, more particularly, to top frame bow construction and the attachment of the top cover to the top frame bows.
Convertible vehicles incorporate a collapsible top structure which comprises a frame including spaced articulated side linkages and a fabric cover. The top is lowered by articulating the linkages which collapses the frame and folds the cover for storage in a storage well behind the vehicle passenger compartment. Top movement may be by manual or power operation.
The top frame generally has spaced side linkages, each of which comprise front, center, and rear side rails and control links pivoted to the vehicle body. The top frame also includes four or five transverse cross bows, termed the header, or #1 bow, and the #2, #3, #4, and #5 bows which interconnect the articulated side linkages. A fabric top cover is supported by and is secured to the header and the transverse bows to assure movement with, and folding by, the frame as it collapses upon top lowering and unfolds upon top raising. In a four bow top, the rear edge of the top cover is attached to the vehicle body. In a five bow top, the rear edge of the top cover is attached to the #5 bow, which is movable relative to the vehicle body.
A backlite is conventionally sewn into a panel located in the top cover between the #4 bow and either the body or the #5 bow. The #2, #3, and #4 bows are bent near their ends to give curvature to the sides of the raised top. Longitudinally-extending side and rear stay pads are located atop the bow bends beneath the top cover to prevent sagging of the fabric at the cover side curvature.
Conventionally, the bows are made of rolled steel channels which contain wood or plastic tacking strips. Spaced transverse fabric flaps are sewn to the fabric cover. The top is assembled front to back. The front of the cover and the front of the stay pads are stapled, or "tacked", to the header tacking strip. The flaps and the side stay pads are then stapled to the tacking strips of the #2 and #3 bows. The rear ends of the side stay pads, the top ends of the rear stay pads, a flap, and the top of the backlite panel are stapled to the #4 bow tacking strip. The cover rear edge and the bottom ends of the rear stay pads are stapled to the #5 bow tacking strip or to the vehicle body around the top of the storage well.
With so many staples, it is not uncommon for staples to engage other staples and break, leaving upstanding sharp points. If these broken staples are not noticed immediately and removed, they will pierce the cover fabric when it is fully installed and render the top defective. This requires replacement of the fabric cover, which is an expensive and time-consuming process.
This conventional installation, or "trimming" of the fabric cover on a convertible top frame, using the above described techniques, is a tedious, time consuming and expensive procedure. Convertible top fabric covers are, by their nature, less durable than the vehicle itself. It is common to replace the fabric cover several times during the life of the vehicle. Replacement of the fabric cover requires removing the staples and tacks and detaching the other connections between the cover and bows to remove the fabric cover. The trimming process must then be repeated to mount the new cover.
It would be desirable to provide a convertible top which enables a simpler, quicker, and cheaper means of trimming the top.
It would also be desirable to provide a top structure which incorporates cover attachments to the bows that facilitate top cover installation and replacement.
An additional problem produced by the trimming of a convertible top with conventional bows is the incidence of bow "read through". This phenomenon is the visible outline of the bows which projects or "reads" through the tautened fabric cover when the top is raised and latched. This detracts from the aesthetic appearance of the top.
Thus, it would be desirable to provide a convertible top having bows that reduce or eliminate the phenomenon of bow "read through" when the top is raised and latched.
An increasingly important consideration in passenger vehicle design and manufacture is total vehicle weight. It is desirable to reduce the weight of all vehicle components including the convertible top mechanism.